A review on hybrid nanolaminate materials synthesized by deposition techniques for energy storage applications
Nanostructured materials such as nanocomposites and nanolaminates are currently of intense interest in modern materials research. Nanolaminate materials are fully dense, ultra-fine grained solids that exhibit a high concentration of interface defects. They may be developed for engineering applications that take advantage of enhanced mechanical properties or for devices such as energy storage and memory storage capacitors. Nanolaminates can be grown using atom-by-atom deposition techniques that are designed with different stacking sequences and layer thicknesses. The properties of fabricated nanolaminates depend on their compositions and thicknesses. These can be demonstrated within the synthesis process by thickness control of each layer and interfacial chemical reaction between layers. In fact, dielectrics with the formed thin layer have efficient dielectric constant and high insulation characteristics. Dielectric materials with giant dielectric constants can be fabricated as modified single, binary and perovskite oxides. A review of the advantages offered by nanolaminate structures for high performance energy storage devices is presented. Developments of dielectric materials that are formed from a thin layer approach are evaluated. The influence of the interface layer on the dielectric constant of nanolaminate films is assessed from the perspective of conferring a giant dielectric constant and high insulation characteristics. The incorporation of dopants and site-engineering techniques, as well as layer-by-layer structures, which can both be suitable for improving dielectric properties of dielectric nanolaminates, is detailed. Finally, the current status and development of artificial dielectric materials for high performance energy storage devices formed by dielectric nanolaminates are presented.